Printing device



July 21, 1931. e. A. FRIESS PRINTING DEVICE Filed Nov. 27. 1929 4 Sheets-Sheet l I Hllh runhhjy 19 ZZHIHM.

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Z ATTORNEY 5 July 1, 1931. e. A. Fmgss PRINTING nvxca Filed Nov. 27. 1929 4 Sheets- Sheet 4 I INVENTOR Z ATTORNEY Patented uly 21, 1931 GUSTAVEA. FRIESS, F FOREST HILLS, NEW YORK ERINTING DEVICE Application filed November 27, 1929. Serial No. 410,203.

My invention relates to devices adapted for printing presses and refers particularly to doctor blade devices especially adapted for use with intaglio printing rollers.

In the process of printing by means of intaglio, and similar, printing rollers it is necessary to remove from the roller the excess of ink upon its surface impression.

This is accomplished by means of a plate, known as a doctor blade, which abuts upon the face of the roller and has a horizontal oscillating movement thereover.

The doctor blade must abut upon the roller face in such a manner as to remove the superficial surface ink without removing it from the engraved portions thereof, and must have an oscillating movement in order that its abutting edge will not wear ofi unevenly.

\ The universally employed doctor blades are formed of a sheet of comparatively thick steel, never less than points in thickness, backed up by a somewhat thicker sheet of steel about 18 to 20 points in thickness, the dpctor blade extending beyond the'backing ate. p Doctor blades of this character have many practical disadvantages.

The abutting edge of the blade is POSI- tioned angularly with respect to the roller face, and because of its thickness it is necessary that this abutting edge be ground off to a sharp angle, the acute angle of the doctor blade abutting upon the roller.

The abrasion between the roller soon wears away this acute angle into an obtuse one, in which event, a broad surface of the doctor blade abuts upon the roller, allowing ink to 40 pass by, producing imperfect prints. Hence, it is necessary to frequently remove the blade and grind it into its original form, and this grinding operation is extremely difiicult of successful operation as the entire edge of the blade must be absolutely uniform and of perfectly straight line or it will not operate evenly throughout the entire length of the roller. A further diificulty incident to this grinding operation is that it destroys the temper of the steel, thus producmga device which does not have the proper resiliency for prior to the printing.

perfect contact and which because of its softness wears down even more rapidly than the original blade.

A further disadvantage of the present employed doctor blades is that the backing plate, being resilient, does not produce a uniform pressure of the blade throughout the length of the roller, thus causing a waving effect and producing unequal print-effects.

Doctor blades must be held rigidly between their two supported ends in order that their abutment upon the roller may be uniform throughout its length.

The present employed blades are too thick to be tensioned and if a thinner blade is used it has a vibrating movement because of the resiliency of the backing member, causing uneven and intermittent pressure upon the roller resulting in uneven prints.

The device of my invention overcomes the above mentioned, and other, objectionable attributes of the present employed doctor blades and presents a doctor blade obviating the necessity of frequent grinding, capable of uniform tensioning, causing a uniform pressure throughout the roller length, preventing vibration and hence producing uniform and equal print elfects.

My invention comprises in general a doctor blade of sufficient thinness, below 10 points, to allow of tensioning, so supported as to prevent objectionable vibration and to cause uniform pressure upon all parts of the roller at all times.

My device comprises a doctor blade of less than 10 point thickness, means for tensioning said blade and a rigid backing to said blade whereby vibration will be prevented and uniform pressure upon the roller will be obtained.

I have found that if a doctor biade be made of thin steel, say about 4 point, the edge will be so thin that the wear upon it will not greatly affect its angular formation, and that, in fact, it can be used almost continuously with out the necessity of grinding, thus overcoming this objectionable feature of the present employed blade.

I have further found that blades of this thickness can be so tensioned as to present a un form pressure upon ,the roller throughout its entire length. I

I have further found that blades of this character can be rigidly backed up, or reinforced, to prevent vibration during use.

The above mentioned, and other, valuable features of the device of my invention will be evident upon a consideration of my specification and accompanying drawings which indicate its great advancement in the art and its lmprovements over the present employed devices.

In the accompanying drawings illustrating modified forms of the device of my invention, 1

similar parts are designated by similar numerals.

Figure 1 is a top view of one form of the dev1 ce of my invention.

Figure 2 is an enlarged top view of the left sideof Figure 1.

Flgure 3 is a section through the line 3-3 of Figure 2.

Figure 4 is an enlarged section through the line 44 of Figure 1. Y

Flgure 5 is a perspective view of the elements comprising the tensioning mechanism.

Figure 6 is a perspective view of the abutment element.

' Figure 7 is a section through the line 7 -7 of Figure 2.

Figure 8 is an end view of Figure 9 showing a modified form of tensioning mechanism.

Figure 9 is a plan view of Figure 8.

Figure 10 is a section through the line 1010 of Figure 11 showing a modified form of tensioning mechanism.

Figure 11 is a section through the line 1111 of Figure 10.

The particular form of the device of my invention shown in Figures 1 to 7 inclusive comprises a base plate 15 having a plurality of extended eye members 16, 16. Abutting upon the upper face of the base plate 15 and extending over one edge thereof is a doctor blade 17. Positioned above and upon the base plate 15 and the doctor blade 17 is a clamping plate 18 fixedly attached to the base plate 15 by means of threaded bolts 19, 19. Positioned above and upon the clamping plate 18 is an angle shaped rigidity member 20, fixedly attached to the clamping plate 18 by means of the threaded bolts 21, 21.

, Positioned at each end of the device as above described and within a cut-out of the doctor blade 17 is an abutment member 22 fixv edly attached to the clamping member 18 by means of the threaded bolts 23. the upper portion of the member 22 being formed into the angular dove-tail 24 for purposes described later.

A blade tensioning mechanism comprises the base plate 25 having the cylindrical opening 26 in one portion thereof, a plurality of threaded openings 27 27 and a plurality of elliptical openings 28, 28. Placeable within ing member 18.

the cylindrical opening 26 are two semi-cylindrical members 29 and 30, the member 29 having the two pins 31, 31 capable of insertion within the holes 32, 32 of the member and the member 30 carrying the two extended threaded bolts 33 capable of passage through the threaded holes 34, 34 of the member 29. The members 29 and 30 are longitudinally tongued and grooved at 35, 36.

In aflixing each end of the doctor blade 17 to the gripping cylinders 29, 30, the plns 31, 31 are passed through the holes 37, 37 of the doctor blade and the threaded bolts 33, 33 are threaded through the holes 38, 38 of the doctor blade 17. The blade 17 is thus forced into, and held within, the tongue and grooves 35, 35, 36, 36. Each gripping cylinder is then placed within an opening 26 of the base plate 25, the blade 17 passing through the vertical slot 39, and held in position by the set-screws 40, 40, 40. Threaded bolts 41, 41 pass through the elliptical holes 28, 28 of the base plate 25 and into threaded holes in the clamp- It will thus be seen that by loosening the bolts 41, 41, the entire tensioning mechanism can be moved longitudinally with respect tothe other portions of the device. This longitudinal movement can be accomplished by means of the turn-buckle 42, abutting upon the abutment member 22 and the cylindrical portion of the base plate 25, the portion of the turn-buckle upon-the abutment 22 being formed to fit the dove-tail 24 and the portion abutting upon the cylindrical member being formed to fit the notched portion of the latter. When the desired tension upon the doctor blade has been obtained by means of the turn-buckle, the bolts 41, 41 are threaded home thus fixing the tensioning mechanism with respect to the other parts of the mechamsm.

Thedoctor blade 17 is so positioned that it dent to all devices of this character and is not,

a part of my invention.

In the modified form oftensioning mechanism shown in Figures 8 and 9, the turnbuckle 42 is replaced by a cam, comprising the elliptical member 44 fixedly attached to the oif-set revoluble pin 45 to which is also attached the link 46 the free end of the link 46 having two extended arms 47 47, each having a longitudinal slot 48 therein. A pin 49 passing through the slots 48, 48 also passes through a hole in the tensioning arm, or rod 50. ,The tensioning rod 50 passes through an opening in the extension 51 of the clamping plate 18, the lower end of, the rod 50 being threaded to receive the nut 52. It is evident that the tensioning of the doctor blade 17 can be accomplished by turning the nut 52.

Inthe modified form of tensioning mechanism shown in FigureslO and 11, the turnbuckle 42 is eliminated and the semi-cylindrical devices shown in Figures 1 to 7 inclusive is replaced by a cylindrical member 53, one

portion of which 54 is cut out to accommodate a plurality of holding screws 55, 55. The doctor blade 17 is passed around the face of the member 53 and through a slot therein and the holding screws 55, 55 are passed through openings therein and threaded home, thus clamping the blade 17 to the cylinder 53. The lower portion 56'of the cylinder 53 is reduced in size and is threaded upon its lower portion which extends through an opening in the bottom of the cylindrical portion of the base 25 and has a lock-nut 57 thereon. The doctor blade 17 is tensioned by turning the cylinder 53 and when the proper tension is obtained is fastened in position by means of the lock-nut 57.

The above sets forth the device of my invention, from which its advancement and value over the present employed devices are clearly evident.

I do not limit myself to the particular size, I

shape, number or arrangement of parts as shown and described, as these are given simply to clearly explain the device of my invention.

" What I claim is 1. In a printing device, in combination, an immovable flexible doctor blade and rigid means for holding said doctor blade, said doctor blade extending beyond said holding means and means capable of longitudinally tensioning said blade,

2. In a printing device, in combination, a pluralit of rigid holding members and an immova le flexible doctor blade positioned between and supported by said holding members, said doctor blade extending beyond said holding members and means capable of longitudinally tensioning said blade.

3. In a printing device, in combination, a plurality of rigid holding membersand an immova le flexible doctor blade positioned between and abutting upon said holding members, said doctor blade extending beyond said holding members and means capable of longitudinally tensioning said blade.

4. In a printing device, in combination, a base plate, a clamping plate, an immovable flexible doctor blade positioned between said base plate and said clamping plate, a rigid member permanently abutting upon said extended portion of said doctor blade and means connecting said base plate, said clamping plate and said doctor blade and means capable of longitudinally tensioning said blade.

5. In a printing device, in combination, a base plate, a clamping plate, an immovable,

flexible doctor blade positioned between said base plate and said clamping plate, a rigid member permanently abutting upon said extended portion of said doctor blade, means connecting said base plate, said clamping plate and said doctor blade, and means for tensioning said doctor blade.

6. In a printing device, in combination, a base plate, a clampingplate, an immovable flexible doctor blade positioned between said base plate and said clamping plate, a rigid member permanently abutting upon said extended portion of said doctor blade, means for attaching said clamping plate to said base plate and means for attaching said rigid member to said clamping plate and means capable of longitudinally tensioning said blade.

In a printing device, in combination, a base plate, a clamping plate, an immovable flexible doctor blade positioned between said base plate and said clamping plate, a rigid member permanently abutting upon said extended portion of said doctor blade, means for attaching said clamping plate to said base plate, means for attaching said rigid member to said clamping plate and means for tensioning said doctor blade.

8. In a printing-device, in combination, a base plate, a clamping plate, a flexible doctor blade positioned between said base plate and said clamp-ing plate, a rigid member abutting upon said extended portion of said doctor blade, a tensioning member capable of longitudinal movement with respect to said base plate, means for fixing said tensioning member with respect to said base plate, means connecting said doctor blade to said tensioning member and means for moving and maintaining said tensioning member.

9. In a printing device, in combination, a base plate, a clamping plate, a flexible doctor blade positioned between said base plate and said clamping plate, a rigid member abutting upon said extended portion of said doctor blade, anabutment member positioned in fixed relationship to said base plate, a tensioning member capable of longitudinal movement with respect to said base plate, means connecting said doctor blade with said tensioning member, and means positioned between said abutment member and said tensioning member capable of moving and maintaining said tensioning member.

10. In a printing device, in combination, a base plate, a clamping plate, a flexible doctor blade positioned between said base plate and said clamping plate, a rigid member abutting upon said extended portion of said doctor blade,an abutmentmember positioned in fixed relationship to said base plate, a tensioning member comprising a base plate having a cylindrical portion, a holding member within said cylindrical portion, means for attaching said doctor blade to said holding member and means for moving and maintaining said tensionin member..

11. n a printing device, in base plate, a clamping plate, a blade positioned between said clamping plate, a rigid member abutting upon said extended portion of said doctor blade,an abutment memberpositioned in fixed relationship to said base plate, a tensioning member comprising a base plate having a cylindrical portion, two-abutable holding members within said cylindrical member, means for holding said doctor blade between said holding members and means for moving and maintaining said tensioning member.

Signed at New York city, in the county of New York and State of New day-of November, 1928.

GUSTAVE A. FRIESS.

combination, a flexible doctor said base plate and- York, this 25th I 

